[Intel-gfx] [PATCH] drm/mm: Use debugobject to track lifetimes
Chris Wilson
chris at chris-wilson.co.uk
Thu Mar 12 11:19:25 UTC 2020
Since drm_mm_node are intended to be embedded into larger structs, we
can use the DEBUG_OBJECTS facility to help track the lifetime of the
drm_mm_node and ensure that they are not being used after the containing
object has been freed, along with the usual verification that the
drm_mm_nodes are being used correctly.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/Kconfig | 13 +++++++
drivers/gpu/drm/drm_mm.c | 55 ++++++++++++++++++++++++++++
drivers/gpu/drm/i915/gt/gen6_ppgtt.c | 2 -
drivers/gpu/drm/i915/i915_vma.c | 17 +++++++--
include/drm/drm_mm.h | 31 ++++++++++++++++
5 files changed, 113 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 43594978958e..33ac38be55b0 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -54,6 +54,19 @@ config DRM_DEBUG_MM
If in doubt, say "N".
+config DRM_DEBUG_MM_OBJECTS
+ bool "Use debugobjects to track live drm_mm_nodes"
+ default n
+ depends on DRM_DEBUG_MM
+ depends on DEBUG_OBJECTS
+ help
+ Enable allocation tracking of memory manager and leak detection on
+ shutdown.
+
+ Recommended for driver developers only.
+
+ If in doubt, say "N".
+
config DRM_DEBUG_SELFTEST
tristate "kselftests for DRM"
depends on DRM
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index bc6e208949e8..073b417bdd7a 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -150,6 +150,41 @@ static void save_stack(struct drm_mm_node *node) { }
static void show_leaks(struct drm_mm *mm) { }
#endif
+#ifdef CONFIG_DRM_DEBUG_MM_OBJECTS
+
+static struct debug_obj_descr drm_mm_debug_descr = {
+ .name = "drm_mm_node",
+};
+
+static inline void debug_node_init(struct drm_mm_node *node)
+{
+ debug_object_init(node, &drm_mm_debug_descr);
+}
+
+static inline void debug_node_activate(struct drm_mm_node *node)
+{
+ debug_object_activate(node, &drm_mm_debug_descr);
+}
+
+static inline void debug_node_deactivate(struct drm_mm_node *node)
+{
+ debug_object_deactivate(node, &drm_mm_debug_descr);
+}
+
+static inline void debug_node_free(struct drm_mm_node *node)
+{
+ debug_object_free(node, &drm_mm_debug_descr);
+}
+
+#else
+
+static inline void debug_node_init(struct drm_mm_node *node) { }
+static inline void debug_node_activate(struct drm_mm_node *node) { }
+static inline void debug_node_deactivate(struct drm_mm_node *node) { }
+static inline void debug_node_free(struct drm_mm_node *node) { }
+
+#endif
+
#define START(node) ((node)->start)
#define LAST(node) ((node)->start + (node)->size - 1)
@@ -428,6 +463,8 @@ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
if (adj_start > node->start || adj_end < end)
return -ENOSPC;
+ debug_node_activate(node);
+
node->mm = mm;
__set_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
@@ -543,6 +580,8 @@ int drm_mm_insert_node_in_range(struct drm_mm * const mm,
}
}
+ debug_node_activate(node);
+
node->mm = mm;
node->size = size;
node->start = adj_start;
@@ -587,6 +626,7 @@ void drm_mm_remove_node(struct drm_mm_node *node)
DRM_MM_BUG_ON(!drm_mm_node_allocated(node));
DRM_MM_BUG_ON(drm_mm_node_scanned_block(node));
+ debug_node_deactivate(node);
prev_node = list_prev_entry(node, node_list);
@@ -618,6 +658,8 @@ void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
struct drm_mm *mm = old->mm;
DRM_MM_BUG_ON(!drm_mm_node_allocated(old));
+ debug_node_deactivate(old);
+ debug_node_activate(new);
*new = *old;
@@ -639,6 +681,19 @@ void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
}
EXPORT_SYMBOL(drm_mm_replace_node);
+void __drm_mm_node_init(struct drm_mm_node *node)
+{
+ debug_node_init(node);
+}
+EXPORT_SYMBOL(__drm_mm_node_init);
+
+void __drm_mm_node_fini(struct drm_mm_node *node)
+{
+ DRM_MM_BUG_ON(drm_mm_node_allocated(node));
+ debug_node_free(node);
+}
+EXPORT_SYMBOL(__drm_mm_node_fini);
+
/**
* DOC: lru scan roster
*
diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
index f4fec7eb4064..0c34d4dd6458 100644
--- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
@@ -359,8 +359,6 @@ static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size)
i915_active_init(&vma->active, NULL, NULL);
- kref_init(&vma->ref);
- mutex_init(&vma->pages_mutex);
vma->vm = i915_vm_get(&ggtt->vm);
vma->ops = &pd_vma_ops;
vma->private = ppgtt;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 5b3efb43a8ef..64140d51ae2c 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -45,11 +45,24 @@ static struct i915_global_vma {
struct i915_vma *i915_vma_alloc(void)
{
- return kmem_cache_zalloc(global.slab_vmas, GFP_KERNEL);
+ struct i915_vma *vma;
+
+ vma = kmem_cache_zalloc(global.slab_vmas, GFP_KERNEL);
+ if (!vma)
+ return NULL;
+
+ kref_init(&vma->ref);
+ mutex_init(&vma->pages_mutex);
+ drm_mm_node_init(&vma->node);
+
+ return vma;
}
void i915_vma_free(struct i915_vma *vma)
{
+ drm_mm_node_fini(&vma->node);
+ mutex_destroy(&vma->pages_mutex);
+
return kmem_cache_free(global.slab_vmas, vma);
}
@@ -114,8 +127,6 @@ vma_create(struct drm_i915_gem_object *obj,
if (vma == NULL)
return ERR_PTR(-ENOMEM);
- kref_init(&vma->ref);
- mutex_init(&vma->pages_mutex);
vma->vm = i915_vm_get(vm);
vma->ops = &vm->vma_ops;
vma->obj = obj;
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index d7939c054259..514685590603 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -275,6 +275,37 @@ static inline bool drm_mm_initialized(const struct drm_mm *mm)
return mm->hole_stack.next;
}
+/* stubs for external module compatiblity */
+void __drm_mm_node_init(struct drm_mm_node *node);
+void __drm_mm_node_fini(struct drm_mm_node *node);
+
+/**
+ * drm_mm_node_init - Prepare a node for use.
+ *
+ * Drivers should clear the drm_mm_node prior to use. If debug is enabled,
+ * the lifetime of the embedded drm_mm_node will be tracked.
+ */
+static inline void drm_mm_node_init(struct drm_mm_node *node)
+{
+#ifdef CONFIG_DRM_DEBUG_MM_OBJECTS
+ __drm_mm_node_init(node);
+#endif
+ memset(node, 0, sizeof(*node));
+}
+
+/**
+ * drm_mm_node_fini - Finalize a node for use.
+ *
+ * Drivers should indicate that the drm_mm_node is finished, and its
+ * state will then be verified by drm_mm.
+ */
+static inline void drm_mm_node_fini(struct drm_mm_node *node)
+{
+#ifdef CONFIG_DRM_DEBUG_MM_OBJECTS
+ __drm_mm_node_fini(node);
+#endif
+}
+
/**
* drm_mm_hole_follows - checks whether a hole follows this node
* @node: drm_mm_node to check
--
2.20.1
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